New concept would make energy, fertilizer from wastewater

When life gives you lemons, make lemonade. When it gives you wastewater, turn it into electricity and fertilizer.

That’s part of the concept behind a new approach to wastewater treatment the Charles River Watershed Association is supporting. With every flush of the toilet, there could be an opportunity conserve water, generate electricity and make a profit, according to proponents of Community Water and Energy Resource Centers approach.

In a new 75-page report, the Charles River Watershed Association calls for a network of small, decentralized, local wastewater treatment facilities. In would go sewage and food waste; out would come clean water and fertilizer, which could then be sold. Along the way, the treatment process would give off methane, which could be used to generate electricity. Thermal energy given off during the process could also be captured and used locally to heat buildings.

Nearby town trialing system

The Town of Littleton has already embraced the model, which is called CWERC, or Community Water and Energy Resource Centers. Town Meeting recently appropriated $450,000 for planning and design work on what is believed to be the first CWERC treatment plant in the United States.

Littleton Selectman Paul Glavey said the town began working with the Charles River Watershed Association several years ago, when it first contemplated installing sewers in the Littleton Common area, which has septic systems instead of municipal sewers.

“If we’re going to do sewering, why do a traditional sewer when we have the opportunity to do something that was cutting-edge, but much more environmentally responsible?” Glavey said.

He hopes to have a CWERC system online within a few years and wants Littleton to become a model to other communities.

New model more efficient

The concept behind CWERCs represents a significant departure from current wastewater management. Traditionally, wastewater has been piped to a large plant at the end of a sprawling regional sewer system. The Deer Island treatment plant, which cost $4 billion when it opened in 2000, treats wastewater from more than 40 communities in Greater Boston, for example.

“Right now, we spend a lot of money treating wastewater, then discharge it into the ocean,” said Julie Wood, a project manager with the Charles River Watershed Association.

Treating water closer to the source, she said, would allow that water to remain in the watershed it came from. Cities and towns could sell that treated water to be used for irrigation, street sweeping, flushing toilets and other applications. Solid waste could be converted into fertilizer and then sold.

Producing electricity and capturing thermal energy closer to the source would be more efficient because there would be less of an opportunity for energy to be lost along the way, Wood said.

Would system work in Bedford?

Bedford is currently part of the Massachusetts Water Resources Authority, which means that the town has its wastewater treated at the Deer Island facility. According to Department of Public Works Director David Manugian, the town currently uses a system where wastewater that is discharged from homes is collected in 30 different pumping stations in the town, which then pump the water to a larger facility on Great Road across from the DPW building which transfers the water over to a MWRA sewer line in Lexington which takes the wastewater the rest of the way to Deer Island.

Manugian said the town is open to new ideas, but the system proposed in Littleton wouldn't necessarily be the best system for Bedford.

"We are always open-minded to solutions to wastewater, and there is a appeal to taking care of your wastewater in your own town," Manugian said. "I've seen some presentations by the CWRA and one of the issues I think it might have in Bedford is that once you treat that water you still need to discharge it somewhere, such as putting it back in the ground and you need a lot of open space to do that. I think the system is a better fit in a more rural community with more open space."

MWRA sticking with Deer Island

Fred Laskey, executive director of the Massachusetts Water Resources Authority, said he doesn’t envision anyone walking away from an investment as massive as Deer Island in his lifetime. But he said CWERCs could potentially one day supplement the MWRA’s traditional sewer infrastructure in some areas.

“What they’ve done is outline some very intriguing concepts,” he said.

Adding that “it may not be the right fit for all locations,” Laskey said the concept is worth considering and examining more closely.